One of the main aspects of my job as an ecologist is conducting reptile surveys – sadly I’ve never conducted one in or around Grantham but I would love to know what can be found in the local area. If you have seen any reptiles, I would love to know – as would ARG UK who have the Record Pool where you can record your sighting.
The standard way to survey for reptiles is to lay down sheets of refugia – often metal tins, carpet tiles or pieces of roofing felt are used – in suitable reptile habitat, then come back and check to see any reptiles which are either sheltering underneath them or using them to warm up as the sun heats the refugia. This works very well with some species but is less successful at detecting others, such as adders. An alternative way is to approach suitable basking spots, such as log piles, stones or nice south-facing ground early in the day (before it gets too warm and the reptiles move off to forage) and see if you can spot one before it spots you!
The one species I have encountered around Grantham is the grass snake, this is a non-venomous species which is often found associated with water where it hunts amphibians and small fish. One individual I have seen in the Grantham area was along Grantham Canal on the approach to Denton Reservoir and most recently another along a footpath which passes through Croxton Park but I would not be surprised if it were also present within the town of Grantham itself. It is quite an adaptable species and can often be found in gardens, especially if you have a pond. If you do see one, you have no reason to fear it although its main defence mechanism is to secrete an awful smelling substance which you will be able to smell on your hands for a good while after so please don’t touch! They also do a rather disturbing (and in my opinion overacted) job of playing dead, only uncoiling and moving away when they are sure the danger has passed.
The most characteristic feature of a grass snake is the yellow patches on its neck. It could be confused with the adder, but lacks the zig-zag pattern on the back as well as the red eyes. The only other species you may encounter which looks similar is the slow worm but this is a smaller creature (actually a legless lizard rather than a snake) which is a brown/gold colour. This page has some great pointers to help you identify a grass snake.
The common lizard is another species which may occur in the Grantham area although I do not know of any confirmed sightings since 1979. This is the only lizard you are likely to encounter in this part of the country and is therefore difficult to mistake for anything else! They are small and often shy creatures whose presence is most often only registered as a rustle in the undergrowth as they scurry out of sight. They are quite a common species in some parts of the country and can certainly be found in north Nottinghamshire around the Sherwood Forest area.
The slow worms is actually a legless lizard – this website on Rushcliffe Wildlife suggests they are present in small colonies only a few miles to the north of Grantham. In some parts of the country they are very common with strongholds in the west country where they are regularly encountered in gardens, most often when sheltering under rocks or logs, and are a welcome addition to the pest-control brigade, feeding on small invertebrate prey including small slugs.
The final species which could possibly be encountered in the vicinity of Grantham is the adder – our only poisonous snake. These have been recorded historically but not for almost 40 years now – the last record relates to Salter’s Ford Valley from 1979 according to the data search in this document which I turned up through a quick google search. The habitat typical of adders includes open heathland and moorland as well as rough countryside associated with forest edges. Due to the intensity of agriculture around Grantham, these populations are likely to be isolated and decreases in the availability of habitat in the last 40 years may well have resulted in the population dying out. There is a possibility that they may persist in some of the more isolated locations out to the south of the town towards Stamford.
They will bite if harassed (or trodden on) so do take care if you see anything which you suspect may be an adder. However they will only do so under provocation and in self defense – they will not attack people without good reason! Reports of adders along canals and waterways such as Grantham Canal are almost always a mid-identification of a harmless grass snake which has a great affinity for water where it will swim to hunt. More details on identification can be found here.
The other native species – smooth snake and sand lizard – are very specific in their habitat requirements and would not be found in or around Grantham.
I hope this quick guide is useful and don’t forget to record any sightings of reptiles or amphibians in the Grantham area on the Record Pool.